Biology 11- Invertebrates test

Molluscs (Bivalves)

-two pieced, hinged shell

-adults mostly sessile, mainly aquatic, some burrowers

-filter feed using gills

-clams, oysters, mussels

Echinoderms

-5 types of echinoderms: sea urchins+sand dollars, brittle stars, sea cucumbers, sea stars, sea lilies+feather star

-echinoderm means "spiny skin"

-characterized by spiny skin, internal skeleton, water vascular system, and suction-cup like structures called tube feet.

-adults have 5 part radial symmetry

-they can scrape algae from rocks (sea urchins), grab plankton with tube feet (sea stars), or bulldoze over the ocean floors (sea cucumbers)

-wastes excreted through anus, or nitrogenous wastes through thin-wall tissues into water.

-nerve ring surrounds the mouth/sensory cells throughout body

-move using tube feet

-reproduce by external fertilization

Animals- General

-All animals are EUKARYOTIC HETEROTROPHS

-They do not have cell walls (like plants do)

-They are ALL are multicellular, which allows for groups of cells to have special functions (eg. tissues, organs, organ systems)

7 essentil functions for survival

1. FEEDING...herbivores, carnivores, parasites, filter feeders, detritus feeders

2. RESPIRATION...all animals use cellular respiration to get energy from food

3. INTERNAL TRANSPORT...method of carrying 02, nutrients and wastes around the body(circulatory system)

4. EXCRETION... diffusion/excretory system

5. RESPONSE...response to stimuli and hunting prey/escaping pred. (nervous system)

6.MOVEMENT... sessile/motile... vertebrae/invert.

7.REPRODUCTION...sexes can change throughout life span, everything varies.

8 phyla of invertebrates

sponges

cnidarians

worms (platyhelminthes, nematodes, annelids)

molluscs

arthropods

echinoderms

Sponges

-evolved 540 million yrs ago

-phylum name: porifera (meaning pore-bearers)

-sessile, multicellular, heterotrophic, no cell walls, contain a few specialized cells

-differ from other animals because they don't have a similar mouth/gut and they have no tissues or organs systems

-separated from ancestors before other groups of animals

Cnidarians

-ex sea anemone and jellyfish

-live in waters all over the world

-soft-bodied, carnivorous animals that have stinging tentacles arranges in circles around their mouths

-simplest animals to have radial symmetry and specialized tissue

-two stages: polyp and medusa

-3 layers body wall: epidermis, mesoglea and gastroderm (inner lining of gastrovascluar cavity, where food is digested

-mouth is where food goes in/out

-they do not need respiratory, excretory or circulatory systems because they use diffusion

- some do not need to eat because of symbiotic photosynthesis protists

-they have muscles and a hydrostatic skeleton

-move using water and contracting their bodies.

Worms (Platyhelminthes)

-flatworms

Worms (Nematoda)

-roundworms

Worms (Annelids)

-segmented worms

Molluscs /features

-clams, oysters, mussels, squid, octopi

-soft-bodied usually with a shell

-all have a similar body plan with trocophore and larvae stages

-They have a radula

-adults show bilateral symmetry

-show every mode of feeding

-eat with radula, a tongue with sharp teeth on it

-breathe through gills

-open circulatory system except cephalopods (octopi/squid)

-excretion by tube-shaped nephridia

-2 sexes and fertilization is external...(slugs are both sexes)

Molluscs (Gastropods)

-have singular shell or none

-move with muscular ventral foot

-aquatic/terrestrial

-use shell/bad taste/poison as defense

-slugs/snails

Molluscs (Cephalopods)

-head is attached to the muscular ventral foot which has been modified over the years into tentacles

-octopi have 8 tentacles, squid+cuttlefish 10, nautili many

Arthropods

-4 subphyla

-Trilobita (trilobites)

-Chelicerata-->class arachnida (spiders, scorpions, ticks...)-->class merestomata (horseshoe crab)

-Crustaceans (lobsters, crabs)

-Uniramia-->class chilopoda (centipedes)-->class diplopoda (millipedes)-->class insecta (caterpillars, beetles...)

Sponge features

movement: sessile

symmetry: asymmetrical, not front/back/left/right

Feeding: filter feeders

Respiration, circulation and excretion: the movement of water + diffusion

response: toxins and poisons against pred.

reproduction: sexual(internal fertilization->one sponge has egg+sperm)/asexual

(budding/gemmules)

complexity: not complex

Cnidarian feeding

-cnidarians paralyze their prey using cnidocytes (stinging cells) with nemocyts (poison filled darts)

-after paralyzing their prey, cnidarians pull the prey through their mouth and into the gastrovascular cavity, where digestion begins.

-digestion is extracellular(outside of cells)

-end of digestion is intracellular(inside cells)

-partially digested food is absorbed by the gastroderm

-un-digestible materials are passed out of the mouth

cnidarians features

-radially symmetrical

-mouth surrounded by tentacles

-2 stages: polyp and medusa

-Respiration, Circulation, and Excretion after digestion, nutrients are transported throughout the body by diffusion.

-Cnidarians respire and eliminate the wastes of cellular metabolism by diffusion through their body walls.

-response: use special sensory cells, have a nerve net all-throughout their body, statocysts sensory cells, and ocelli; eye spots that detect light

-movement; some have a hydrostatic skeleton

reproduction: asexual/sexually---->polyps asexual by budding their offspring is identical. ----->sexualy: external fertilization outside females body....medusas are either male/female

flatworms key features

soft, flattened worms that have tissues and internal organ systems. They are the simplest animals to have three embryonic germ layers, bilateral symmetry, and cephalization. cephalization: yes (head)

roundworms key features

Roundworms are unsegmented worms that have pseudocoeloms and digestive systems with two openings—a mouth and an anus.

segmented worms key features

Annelids are worms with segmented bodies. They have a true coelom that is lined with tissue derived from mesoderm

worms parasite vs free

Free-living flatworms- organ systems for digestion, excretion,response, and reproduction

-head encloses several ganglia, groups of nerve cells, that control the nervous system. +eyespot

-carnivores/detrivores

-move using cilia/muscles

-reproduce sexually

parasitic -simpler in structure

-feed off host/predigested foods

-less complex nervous system

-reproduce asexually by fission ex

-some live between multiple hosts

arthropod features

-bodies divided into segments

-tough/flexible exoskeleton made w/ chitin +waxy cuticle

-have jointed appendages

-herbivores, carnivores, and omnivores

-mouth parts(pincers or fangs)

-breathe with tracheal tubes or book lungs

-open circulatory system with well developed heart

-excretion using malpighian tubes

-well-developed nervous system with brain

-compound eyes(2000 lenses)

-well developed muscles

-internal fertilization/external if aquatic